“Never!” said Dick and Joe together, almost in a shout.

“Onward, then, and may we have the help of Heaven!”

At ten o’clock at night, after passing over ravines, forests, and scattered villages, the aëronauts reached the side of the Trembling Mountain, along whose gentle slopes they went quietly gliding. In that memorable day, the 23d of April, they had, in fifteen hours, impelled by a rapid breeze, traversed a distance of more than three hundred and fifteen miles.

But this latter part of the journey had left them in dull spirits, and complete silence reigned in the car. Was Dr. Ferguson absorbed in the thought of his discoveries? Were his two companions thinking of their trip through those unknown regions? There were, no doubt, mingled with these reflections, the keenest reminiscences of home and distant friends. Joe alone continued to manifest the same careless philosophy, finding it quite natural that home should not be there, from the moment that he left it; but he respected the silent mood of his friends, the doctor and Kennedy.

About ten the balloon anchored on the side of the Trembling Mountain, so called, because, in Arab tradition, it is said to tremble the instant that a Mussulman sets foot upon it. The travellers then partook of a substantial meal, and all quietly passed the night as usual, keeping the regular watches.

On awaking the next morning, they all had pleasanter feelings. The weather was fine, and the wind was blowing from the right quarter; so that a good breakfast, seasoned with Joe’s merry pranks, put them in high good-humor.

The region they were now crossing is very extensive. It borders on the Mountains of the Moon on one side, and those of Darfur on the other—a space about as broad as Europe.

“We are, no doubt, crossing what is supposed to be the kingdom of Usoga. Geographers have pretended that there existed, in the centre of Africa, a vast depression, an immense central lake. We shall see whether there is any truth in that idea,” said the doctor.

“But how did they come to think so?” asked Kennedy.

“From the recitals of the Arabs. Those fellows are great narrators—too much so, probably. Some travellers, who had got as far as Kazeh, or the great lakes, saw slaves that had been brought from this region; interrogated them concerning it, and, from their different narratives, made up a jumble of notions, and deduced systems from them. Down at the bottom of it all there is some appearance of truth; and you see that they were right about the sources of the Nile.”